/Engine/Source/Runtime/Engine/Public/SceneTypes.h
Mark that a view state shares an origin with another view state, allowing sharing of some internal state, saving memory and performance. Typically used for cube map faces. Must be called before "Allocate" is called on the source view state (best practice is to call immediately after creating the view state). Multiple view states can point to the same shared origin (for example, the first face of a cube map), but sharing can't be nested. Sharing view states must be destroyed before the Target is destroyed.
void ShareOrigin ( [FSceneViewStateReference](API\Runtime\Engine\FSceneViewStateReference) * Target )